What is permitted development and what can I build without planning permission?

For homeowners in England planning an extension, loft conversion or outbuilding.

Applies to: England Last checked against official sources: 6 October 2026

Permitted development rights let you make some changes to a house in England without applying for planning permission.

A single storey rear extension can go back 4 metres on a detached house, or 3 metres on other houses, and be up to 4 metres high.
Extensions and outbuildings must not cover more than half the land around the original house.
The rights do not apply to flats or maisonettes, and are limited in places like conservation areas and National Parks.
Your council can remove the rights in some areas with an Article 4 direction.
You still need to follow building regulations.

Different in Scotland, Wales or Northern Ireland

Rules may be different in:

Scotland: Check mygov.scot for Scotland
Wales: Check gov.wales for Wales
Northern Ireland: Check nidirect for Northern Ireland

Key facts

Rear extension: 3m, or 4m if detached
Height limit: 4 metres
Not for flats or maisonettes
Building regulations still apply

What permitted development means

Permitted development rights let you improve or extend a house without a full planning application. The rules are set by national law. If your project fits inside the limits, you do not need planning permission.

These rules are for houses in England. If your project is bigger than the limits, you can still apply for planning permission in the usual way.

When the rights do not apply

You do not have permitted development rights, or they are limited, if:

you live in a flat or maisonette
your house was made by converting another type of building, such as an office or barn
your home is in a conservation area, National Park, Area of Outstanding Natural Beauty, the Broads or a World Heritage Site (some rules are stricter there)
your council has made an Article 4 direction, which removes some rights in your area
the original planning permission for your home removed the rights
your home is a listed building (you cannot build outbuildings in its grounds this way)

Main size limits for houses

Type of work	Main limit
Single storey rear extension, detached house	Up to 4 metres deep, 4 metres high
Single storey rear extension, other houses	Up to 3 metres deep, 4 metres high
Larger single storey rear extension (council must be told first)	Up to 8 metres (detached) or 6 metres (other), 4 metres high
Two storey rear extension	Up to 3 metres deep
Side extension	No wider than half the width of the original house
Loft conversion (extra space)	40 cubic metres (terraced), 50 cubic metres (other houses)
Porch	Up to 3 square metres floor area and 3 metres high, at least 2 metres from a road boundary
Outbuilding, like a shed	Up to 2.5 metres high if within 2 metres of a boundary

Other rules apply too:

Extensions and outbuildings together must not cover more than half the land around the original house.
An extension cannot be higher than the existing roof, and its eaves cannot be higher than the existing eaves.
If an extension is within 2 metres of a boundary, its eaves cannot be over 3 metres high.
Outbuildings can be up to 4 metres high with a dual pitched roof, or 3 metres otherwise, if they are more than 2 metres from a boundary.

How to be sure

Read GOV.UK's technical guidance for householders. It has drawings for each type of work.
Ask your council's planning team if your area has any Article 4 directions.
If you want proof, apply to your council for a lawful development certificate. This confirms the work is lawful without planning permission.

Other permissions you may still need

Permitted development only covers planning. You still need to meet building regulations. If you are working on a wall shared with a neighbour, you may also need a party wall agreement.

If you live in Wales, Scotland or Northern Ireland

These limits are for England. Wales, Scotland and Northern Ireland have their own planning systems. Wales publishes its own householder permitted development guidance, and in Scotland many small alterations and extensions can be made without applying. Check with the Welsh Government, mygov.scot or nidirect before you start.

Related guides

Where this comes from

Get it done

This takes you to the official service, which is free to use.

Contact your local planning authority

Common questions

Can I check if my project is permitted development?

Yes. You can apply to your council for a lawful development certificate, which confirms the work does not need planning permission.

Can I build a bigger rear extension?

Yes, up to 8 metres for a detached house or 6 metres for others, but you must ask the council first so neighbours can be consulted.

Official sources

1.Permitted development rights for householders: technical guidance (GOV.UK)www.gov.uk/government/publications/permitted-development-rights-for-householders-technical-guidance/permitted-development-rights-for-householders-technical-guidance
2.Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 1 Class A (legislation.gov.uk)www.legislation.gov.uk/uksi/2015/596/schedule/2/part/1/crossheading/class-a-enlargement-improvement-or-other-alteration-of-a-dwellinghouse
3.Planning permission: when you do not need it (GOV.UK)www.gov.uk/planning-permission-england-wales/when-you-dont-need-it

Checked against GOV.UK on 6 October 2026

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